day13 类模板案例

实现一个通用的数组类

1、可以将内置数据类型以及自定义数据类型的数据进行存储
2、将数组中的数据存储到堆区
3、构造函数中可以传入数组容量
4、提供对应的拷贝构造函数以及operator=防止浅拷贝的问题
5、提供尾插法和尾删法对数组中的数据进行增加和删除
6、可以通过下标的方式访问数组中的元素
7、可以获取数组中当前元素个数和数组的容量

#pragma once
#include<iostream>
#include<string>
using namespace std;

template<class T>
class Myarray
{
public:
    Myarray(int capacity)
    {
        cout << "拷贝构造函数调用"<< endl;
        this->m_Capacity = capacity;
        this->m_Size = 0;
        this->pAddress = new T[m_Capacity];
    }
    //有数据储存在堆区，因此需要自己构建拷贝构造函数和operator=
    Myarray(const Myarray &arr)
    {
        this->m_Capacity = arr.m_Capacity;
        this->m_Size = arr.m_Size;
        //this->pAddress = new.pAddress//系统默认浅拷贝操作
        T* pAddress = new T[arr.m_Capacity];
        //将arr中的数据都拷贝到新的地方
        for(int i = 0 ; i < m_Size ; i++)
        {
            this->pAddress[i] = arr.pAddress[i];
        }
    }
    //接下来重载operator=操作符
    T& operator=(Myarray &arr)
    {
        if(this-> pAddress != NULL)
        {
            detele[] this-> pAddress;
            this-> pAddress = NULL;
            this->m_Capacity = 0;
            this->m_Size = 0;
        }
        this->m_Capacity = arr.m_Capacity;
        this->m_Size = arr.m_Size;
        T* pAddress = new T[arr.m_Capacity];
        for(int i = 0 ; i < m_Size ; i++)
        {
            this->pAddress[i] = arr.pAddress[i];
        }
        return *this；
    }
    //尾插法  这个没有印象需要怎么做了，这部分写错了
    void Push_Back(int id)
    {
        if(this->m_Size == this->m_Capacity)
        {
            return;
        }
        
        
        this->m_Size ++ ;
    }
    
    //尾删法
    void Pop_Back()
    {
        this->m_Size--;
    }

    //通过下标索引访问数组中元素,重构[]
    T& operator[](int i)
    {
        return this->pAddress[i];
    }

    int getCapacity()
    {
        return this->m_Capacity;
    }   

    int getSize()
    {
        return this->m_Size;
    }   


    ~Myarray()
    {
        if(this->pAddress != NULL)
        {
            delete[] this->pAddress;
            this->pAddress = NULL;
            this->m_Size = 0;
            this->m_Capacity = 0 ;
        }
    }

private:
    T *pAddress;
    int m_Capacity;
    int m_Size;
};

上述代码中 尾插法的代码有问题，在自己实现的时候忘记其本质，下面是尾插法的相关代码

void Push_Back(const T&val) //传递一个类型为 T 的常量引用，函数内部不能修改 val 的值。
{
	//判断容量是否等于大小
	if (this->m_Capacity == this->m_Size) 
	{
		return;
	}
	this->pAddress[this->m_Size] = val;
	this->m_Size++;
}

#include<iostream>
#include<string>
using namespace std;
#include"Myarray.hpp"

void printinfo(Myarray<int> &arr)
{
	for (int i = 0; i < arr.getSize(); i++) 
	{
		cout << arr[i] << endl;
	}
}

void test01() 
{
	Myarray<int> arr1(5);
	//arr1[0];//访问不了，所以要重载[]

	for (int i = 0; i < 5; i++) 
	{
		arr1.Push_Back(i);//尾插法
	}
	arr1.Pop_Back();
	cout << "arr1的打印输出为" << endl;
	printinfo(arr1);
	cout << "arr1的大小：" << arr1.getSize() <<
		" arr1的容量：" << arr1.getCapacity() << endl;
	/*Myarray<int> arr2(arr1);
	Myarray<int> arr3(100);
	arr3 = arr1;*/
	Myarray<int> arr2(arr1);
	Myarray<int> arr3(100);
	arr2 = arr3;
	for (int i = 0; i < arr2.getCapacity(); i++)
	{
		arr2.Push_Back(i);//尾插法
	}
	arr2.Pop_Back();
	cout << "arr2的打印输出为" << endl;
	printinfo(arr2);
	cout << "arr2的大小：" << arr2.getSize() <<
		" arr2的容量：" << arr2.getCapacity() << endl;
}

//自定义数据类型测试
class Person 
{
public:
	Person() {};
	Person(string name, int age) 
	{
		this->m_name = name;
		this->m_age = age;
	}

	string m_name;
	int m_age;
};

void printPersonArray(Myarray<Person> & arr)
{
	for (int i = 0; i < arr.getSize(); i++) 
	{
		cout << "name = " << arr[i].m_name <<
			" age = " << arr[i].m_age << endl;
	}
}
void test02() 
{
	Myarray<Person>arr(10);
	Person p1("Tom", 19);
	Person p2("Jerry", 20);
	Person p3("Sam", 29);
	Person p4("Amy", 14);
	Person p5("daming", 16);
	arr.Push_Back(p1);
	arr.Push_Back(p2);
	arr.Push_Back(p3);
	arr.Push_Back(p4);
	arr.Push_Back(p5);
	printPersonArray(arr);
	cout <<"arr的容量："  << arr.getCapacity() << endl;
	cout << "arr的大小：" << arr.getSize() << endl;
}


int main() 
{
	test02();
	system("pause");
	return 0;
}

这个案例的实现算是其中最容易理解的一个了，可以手敲